Submission to the State Development, Infrastructure and Industry Committee Inquiry “ Audit Office Report to Parliament 14 for 2012- 13: Maintenance of water infrastructure assets”

School of Civil & Environmental Engineering Date: 18 October, 2013.

Author: Dr Stuart Khan Address: School of Civil Environmental Engineering, University of New South Wales. Phone: (02) 93855070 Email: [email protected]

Table of Contents

EXECUTIVE SUMMARY 2

BACKGROUND 3

INTRODUCTION 4

CURRENT OPERATIONAL STRATEGY FOR THE WCRWS 5

PROPOSED OPERATIONAL STRATEGY FOR THE WCRWS 7

DESCRIPTION OF PROPOSED OPERATIONAL STRATEGY 7 ADVANTAGES OF PROPOSED OPERATIONAL STRATEGY 7 IMPROVED AND PROTECTED RAW WATER QUALITY FOR THE MT CROSBY WATER TREATMENT PLANT 7 DIVERSIFICATION OF SOURCE WATER OPTIONS FOR THE MT CROSBY WATER TREATMENT PLANT 9 REDUCED WATER PUMPING REQUIREMENTS 9 AN OPPORTUNITY TO INCREASE FLOOD MITIGATION CAPACITY 9

DIRECT POTABLE REUSE (DPR) 11

WHAT IS DIRECT POTABLE REUSE (DPR)? 11 FINDINGS BY THE ACADEMY OF TECHNOLOGICAL SCIENCES AND ENGINEERING (ATSE) 12

CONCLUDING COMMENTS 14

REFERENCES 15

Executive Summary

This document is presented as a public submission to the State Development, Infrastructure and Industry Committee of the Queensland Parliament Legislative Assembly inquiry into the issued contained in the Queensland Audit Office Report to Parliament 14 for 2012-13: Maintenance of water infrastructure assets.

The focus of this submission is the configuration and operation of the Western Corridor Recycled Water Scheme in relation to the operation of as the major water supply reservoir for South East Queensland. This submission specifically addresses key aspects of the Inquiry Terms of Reference including:

 “innovative strategies to increase revenue from manufactured water infrastructure assets” and

 “the future public value of the assets including consideration of the impact on the community, economy and environment”.

The current operational strategy of the WCRWS is briefly summarised to provide clear context for the central proposal of this submission. An alternative, considerably more advantageous, operational strategy for the WCRWS is then proposed as follows:

1. Construct a new pipeline from the Bundamba AWTP to the Mt Crosby Water Treatment Plant. This would enable water from the three AWTPs to be directly transferred to Mt Crosby for potable use.

2. Reverse the flow of water in the pipeline from the Bundamba AWTP to the “Possible release to Wivenhoe” point. That is, reservoir water from Lake Wivenhoe would be transported in a protected enclosed pipeline to Bundamba. It would then be transferred from Bundamba to Mt Crosby via the new pipeline proposed above.

3. Decommission the section of the pipeline from the “Possible release to Wivenhoe” point to the Tarong Power Station off-take. It is far less energy intensive for the Tarong Power Station to source water from the north-western reaches of Lake Wivenhoe.

Outcomes of the proposed alternative WCRWS configuration are described, including the following:

 Improved and protected raw water quality for the Mt Crosby Water Treatment Plant

 Diversification of source water options for the Mt Crosby Water Treatment Plant

 Reduced water pumping requirements

 An opportunity to increase flood mitigation capacity

It is proposed that there are a broad range advantages to be realised from these outcomes. These include opportunities for improved raw water supply, increased flexibility, significantly increased system resilience, reduced operational costs, reduced energy consumption and greenhouse footprint, and improved mitigation of future flooding events.

An essential aspect of this proposed alternative configuration is known as ‘direct potable reuse’ (DPR) of highly treated recycled water. A brief overview of the concept of DPR is provided, along with the relevant finding of a recent report from the Australian Academy of Technological Sciences and Engineering (ATSE).

2 Background

On 7 June 2013, the State Development, Infrastructure and Industry Committee of the Queensland Parliament Legislative Assembly referred the Queensland Audit Office Report to Parliament 14 for 2012-13: Maintenance of water infrastructure assets to the committee for consideration.

The Queensland Audit Office report examined whether the South East Queensland Water Grid assets, namely the Gold Coast Desalination Plant and Western Corridor Recycled Water Scheme are being managed and maintained effectively to contribute to a secure and sustainable water supply.

In accordance with Section 94 of the Parliament of Queensland Act 2001, the committee has resolved to undertake an inquiry into the issues contained in the Queensland Audit Office Report.

The Terms of Reference for this inquiry state:

“In conducting its inquiry, the committee will:

 examine the issues contained in the Queensland Audit Office Report to Parliament 14 for 2012-13: Maintenance of water infrastructure assets

 consider the value for money of manufactured water infrastructure assets:

o operating and maintenance costs of manufactured water infrastructure assets

o innovative strategies to increase revenue from manufactured water infrastructure assets

o the future public value of the assets including consideration of the impact on the community, economy and environment

 consider the policy framework for decisions to invest in significant bulk water supply infrastructure, or to upgrade current infrastructure.”

This document was prepared as a submission to this inquiry. It addresses the terms of reference as described in the following section.

3 Introduction

This submission specifically addresses key aspects of the Inquiry Terms of Reference including:

 “innovative strategies to increase revenue from manufactured water infrastructure assets” and

 “the future public value of the assets including consideration of the impact on the community, economy and environment”.

No financial determinations regarding “value for money” are provided in this submission. However, an innovative operational strategy for the Western Corridor Recycled Water Scheme (WCRWS) is identified. This strategy has the potential to significantly increase the benefits derived from of the operation of the WCRWS, while concurrently lowering the operational costs.

4 Current operational strategy for the WCRWS

The WCRWS was constructed in accordance with the schematic illustration provided in Figure 1. The key features include:

 Advanced water treatment plants (AWTPs)

o Luggage Point AWTP

o Gibson Island AWTP

o Bundamba AWTP

 Water transfer pipelines

o Luggage Point AWTP to Gibson Island AWTP to Bundamba AWTP

o Bundamba AWTP to Swanbank Power Station

o Bundamba AWTP to Tarong Power Station connection

o “Possible release to Wivenhoe” pipeline

In this arrangement, water is required to be pumped a considerable distance (east to west) from the AWTPs to the Tarong Power Station connection. This is despite the fact that the Tarong Power Station connection is adjacent to an alternative available local water supply (the north-western reaches of Lake Wivenhoe).

If this arrangement were to be used for its full intended purpose, including indirect potable reuse (IPR), water would also be pumped (east to west) from the AWTPs to Lake Wivenhoe. This highly purified water would then be mixed with lower-quality environmental water, before returning back down the Brisbane River to the Mt Crosby Water Treatment Plant. This is an energy-intensive (and hence expensive) exercise in pumping water uphill, in order to allow it to flow back down again. In doing so, the water is exposed to environmental contamination, as well as environmental losses such as by evaporation.

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Figure 1 Schematic illustration of the WCRWS (Gardner & Dennien, 2007).

6 Proposed operational strategy for the WCRWS

A proposed alternative operational strategy for the WCRWS is described below. This alternative strategy involves only minimal additional capital construction (a pipeline between Bundamba and Mt Crosby) and offers a range of highly beneficial advantages to drinking water suppliers and customers in South East Queensland.

Description of proposed operational strategy A considerably more advantageous operational strategy for the WCRWS is described in the following points:

4. Construct a new pipeline from the Bundamba AWTP to the Mt Crosby Water Treatment Plant. This would enable water from the three AWTPs to be directly transferred to Mt Crosby for potable use.

5. Reverse the flow of water in the pipeline from the Bundamba AWTP to the “Possible release to Wivenhoe” point. That is, reservoir water from Lake Wivenhoe would be transported in a protected enclosed pipeline to Bundamba. It would then be transferred from Bundamba to Mt Crosby via the new pipeline proposed above.

6. Decommission the section of the pipeline from the “Possible release to Wivenhoe” point to the Tarong Power Station off-take. It is far less energy intensive for the Tarong Power Station to source water from the north-western reaches of Lake Wivenhoe.

Advantages of proposed operational strategy There are a broad range advantages to be realised from the alternative operational strategy. These include opportunities for improved raw water supply, increased flexibility, significantly increased system resilience, reduced operational costs, reduced energy consumption and greenhouse footprint, and improved mitigation of future flooding events. These advantages are described below.

Improved and protected raw water quality for the Mt Crosby Water Treatment Plant Raw water for the Mt Crosby Water Treatment Plant is currently sourced from the Brisbane River at Mt Crosby. This water is subject to a variety of chemical and microbial contamination sources between release from Lake Wivenhoe and treatment at Mt Crosby. These include agricultural, mining and urban runoff as the river makes its way through farming properties (eg. at ), sand and gravel mines (eg. Parslow Park) and residential areas (eg. Fernvale, Lowood). Furthermore, additional water sources flow into the Brisbane River including the (Gatton, Laidley and considerable agricultural catchment), England Creek, and Sandy Creek, all of which have the potential to deliver chemical and microbial contaminants to Brisbane’s raw water supply.

Examples of the types of environments to which the Brisbane River is exposed between release from Wivenhoe Dam and the intake to the Mt Crosby Water Treatment Plant are presented in Figure 2 (Google Maps, 2013).

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Figure 2 Environments to which the Brisbane River is exposed between release from Wivenhoe Dam and the intake to the Mt Crosby WTP (Google Maps, 2013).

The susceptibility of the Brisbane River to poor water quality was drastically revealed during the January 2013 floods. Extremely poor quality (muddy) water was delivered from the Lockyer catchment, which had been previously heavily damaged from the 2011 flood. This water overwhelmed the Mt Crosby Water Treatment Plant, with turbidity levels soaring to an unprecedented 4000 NTU. The plant was unable to produce drinking water for around 12 hours and, as a consequence, it has been reported that seven suburbs were hours away from running out of water (Thompson, 2013). Eventually, water released from the Wivenhoe Dam flushed the system and the water treatment plant was restarted.

The opportunity to transfer water from Lake Wivenhoe to the Mt Crosby Water Treatment Plant (via Bundamba) in an enclosed pipeline is an opportunity to protect Brisbane’s raw water supply from these significant sources on en-route contamination. This form of source water protection would be highly beneficial for Brisbane’s drinking water quality. Furthermore, it would reduce the treatment burden (and hence operational costs, energy consumption, chemical use and waste production) for the Mt Crosby Water Treatment Plant. Finally, it would provide significant protection against current water quality vulnerability to extreme weather events, such as floods, bushfires and heatwaves.

8 Diversification of source water options for the Mt Crosby Water Treatment Plant The Mt Crosby Water Treatment Plant can currently draw water from only a single source, -the Brisbane River. Consequently, any water quality concerns with this supply can only be addressed through enhanced treatment (as far as practical) and, in extreme cases, the issue of a ‘boil water alert’ to drinking water customers.

The proposed alternative operational strategy would allow water to be sourced from any combination of three options:

1. From Lake Wivenhoe via the enclosed pipeline (and via Bundamba)

2. From the AWTPs (including Bundamba, Luggage Point and Gibson Island AWTPs)

3. From the Brisbane River (as per current practice)

In normal circumstances, these three sources could be optimally selected or blended to optimise water quality, pumping costs and treatment costs at the Mt Crosby Water Treatment Plant.

In circumstances where one or two of these sources may be compromised (eg. through the growth of algae or cyanobacteria, flood run off, or chemical spill), there remains an opportunity to select the best available source. This capability would provide a considerable degree of resilience to the Brisbane water supply.

The flexibility provided by three independent water source options would also bring a number of additional advantages. These include the ability to optimise source blending ratios to achieve water quality (eg. taste, salinity, natural organic matter, hardness, chlorine demand, disinfection by-product formation potential) objectives. Furthermore, individual raw water sources could be shut-down completely for extended periods for maintenance activities.

Reduced water pumping requirements The current configuration of the WCRWS involves pumping water from the Bundamba AWTP to the Tarong Power Station off-take (with possible release to Wivenhoe along the way). This is a much further distance and elevation than would be required in the proposed operational strategy.

The proposed operational strategy would require pumping water from the Bundamba AWTP to the Mt Crosby Water Treatment Plant. It would also require transporting water via the existing pipeline from Lake Wivenhoe to Bundamba. A detailed assessment would need to be undertaken to determine the net savings in water pumping energy and costs. Nonetheless, the transportation of water is well known to be a significant contributor to the overall energy-budget of most municipal water utilities. As such, the energy savings from the proposed reconfiguration are likely to be considerable.

Energy savings will, of course, translate directly to savings in energy costs and in (Scope 2) greenhouse gas emissions. The size of the cost savings may be projected based on expected future trends in electricity pricing in Queensland. Similarly, the significance of the greenhouse gas emissions savings may be projected based on future regulation and control of carbon dioxide emissions in Queensland.

An opportunity to increase flood mitigation capacity In addition to drinking water supply, Lake Wivenhoe also plays an important role in preventing or mitigating downstream flooding events. Unfortunately, these two roles are somewhat conflicted since optimum use for flooding control would require the reservoir to be maintained at relatively low levels, whereas a drinking water supply security requires large volumes of water to be stored to buffer seasonal and annual variations in supply and demand.

9 Reduced reliance on Lake Wivenhoe for drinking water supply security could be achieved by the use of direct potable reuse (DPR) as proposed above (Khan, 2011). If part of the supply security to the Mt Crosby Water Treatment Plant is provided by DPR, Lake Wivenhoe could be maintained at a lower level, thus enhancing flood control, while maintaining certainty of supply for drinking water.

When operating at full capacity, the existing Western Corridor Recycled Water Project (WCRWP) can produce up to 232 ML/day of recycled water. During 2012/13, SEQWater supplied 279 GL drinking water (including water from its dams plus existing use of the WCRWS) (SeqWater, 2013a). This is an average total water consumption of 764 ML/day.

Full supply capacity of Lake Wivenhoe is 1,165,238 ML (SEQWater, 2013b), which is approximately 1520 times the average daily consumption volume. If 232 ML/day were supplied by DPR, the remaining average daily water demand would be (764-232=) 532 ML/day.

In order to maintain maximum storage of 1520 times the average daily consumption volume, only (532 x 1520 =) 811,560 ML would be required. The remaining 353,678 ML of storage volume could then be preserved for flood mitigation.

The current volume reserved for flood mitigation in Lake Wivenhoe is 1,450,000 ML. Accordingly; DPR would enable this to be increased by around 25%. Such additional storage volume may have had significant ramifications during the Brisbane River flooding event of January 2011.

This approach is equivalent to immediately constructing a new 354 billion litre reservoir, without the cost of construction and without having to relocate a single home or farm. In addition to completely avoiding the environmental impacts of new dams, it would enable less water to be captured by the existing dam enhancing natural flow regimes in the river. But most importantly, the freed-up storage space is there to help capture and control major flooding events when they occur.

10 Direct potable reuse (DPR)

The Australian Academy of Technological Sciences and Engineering (ATSE) recently released a report on the potential future role of DPR as a component of drinking water supply in Australia (Khan, 2013). I was the lead author of that report. The front cover of the report is displayed in Figure 3 and a full copy can be downloaded (free of charge) from the ATSE website: www.atse.org.au

Figure 3 Report on direct potable reuse (DPR) recently produced by the Academy of Technological Sciences and Engineering (ATSE). Available from www.atse.org.au

What is direct potable reuse (DPR)? Direct potable reuse (DPR) is the term used to describe a potable water recycling project in which that reclaimed water is reused as a drinking water supply, without return to an environmental system such as a river, lake or aquifer (Leverenz et al., 2011; Arnold et al., 2012). Highly treated water, sourced from reclaimed municipal wastewater, may be transferred directly to a municipal drinking water treatment plant or (even more directly) to a drinking water distribution system. This water may or may not be blended with other water sources.

The use of the term ‘direct’ is intended to distinguish this approach to potable water reuse from the more commonly applied and recognised alternative, ‘indirect potable reuse’ (IPR). The characteristic feature of all IPR schemes is that the reclaimed water is first returned to some form of environmental system (commonly referred to as an ‘environmental buffer’) such as a river, lake or aquifer. From that point, the water may be mixed with other (environmental) sources of water prior to being extracted for further treatment and use as municipal drinking water.

The absence of an environmental buffer in a DPR project does not necessarily imply that there is no capacity for storage to buffer variabilities in water supply and demand. However, it would normally imply that such a storage buffer, should it be used, would be ‘engineered’ rather than ‘natural’ (Tchobanoglous et al., 2011). Furthermore, engineered storage buffers of DPR systems would not normally be assumed to provide any additional treatment benefit, as may often be assumed for environmental buffers.

11 The US EPA Guidelines for Water Reuse describe DPR as follows (US Environmental Protection Agency, 2012):

“DPR refers to the introduction of purified water, derived from municipal wastewater after extensive treatment and monitoring to assure that strict water quality requirements are met at all times, directly into a municipal water supply system. The resultant purified water could be blended with source water for further water treatment or could be used in direct pipe-to-pipe blending, providing a significant advantage of utilizing existing water distribution infrastructure.”

The Guidelines state that DPR may now “be a reasonable option based on significant advances in treatment technology and monitoring methodology in the last decade and health effects data from IPR projects and DPR demonstration facilities”. With specific reference to data collected from a number of US-based IPR projects, the Guidelines conclude that the advanced wastewater treatment processes in place in these projects can meet the required purification level.

The case for including DPR among the various water supply options that may be considered in a particular circumstance is based largely on the potentially advantageous environmental, financial and reliability attributes of DPR compared to some alternatives:

“In many parts of the world, DPR may be the most economical and reliable method of meeting future water supply needs. While DPR is still an emerging practice, it should be evaluated in water management planning, particularly for alternative solutions to meet urban water supply requirements that are energy intensive and ecologically unfavorable. This is consistent with the established engineering practice of selecting the highest quality source water available for drinking water production. Specific examples of energy-intensive or ecologically-challenging projects include interbasin water transfer systems, which can limit availability of local water sources for food production, and source area ecosystems, which are often impacted by reduced stream flow and downstream water rights holders who could exercise legal recourse to regain lost water. In some circumstances, in addition to the high energy cost related to long-distance transmission of water, long transmission systems could be subject to damage from earthquakes, floods, and other natural and human-made disasters. Desalination is another practice for which DPR could serve as an alternative, because energy requirements are comparatively large, and brine disposal is a serious environmental issue. By comparison, DPR using similar technology will have relatively modest energy requirements and provide a stable local source of water.”

Findings by the Academy of Technological Sciences and Engineering (ATSE) In undertaking the development of this report, ATSE developed a series of key findings, as presented in the following paragraphs.

The science, technology and engineering associated with DPR have been rapidly advancing in recent decades. DPR is growing internationally and will be an expanding part of global drinking water supply in the decades ahead.

DPR is technically feasible and can safely supply potable water directly into the water distribution system, but advanced water treatment plants are complex and need to be designed correctly and operated effectively with appropriate oversight. Current Australian regulatory arrangements can already accommodate soundly designed and operated DPR systems.

12 High levels of expertise and workforce training within the Australian water industry is critical. This must be supported by mechanisms to ensure provider compliance with requirements only to use appropriately skilled operators and managers in their water treatment facilities. This will be no less important for any future DPR implementation and to maintain high levels of safety with current drinking water supply systems.

Some members of the community are concerned about the prospect of DPR. Planning, decision- making, and post-implementation management processes should acknowledge and respond to these concerns. Public access to information and decision-making processes needs to be facilitated. However, the relative merits of water supply options should, as far as possible, be based on quantifiable or evidence-based factors such as public safety, cost, greenhouse gas emissions and other environmental impacts, as well as public attitudes. There is little value in distinguishing DPR from other water supply options, unless specific proposals are compared using these criteria. Any proposal to consider DPR alongside alternative water supply options should explicitly take account of full life cycle costs, long term sustainability (including pricing) and full costing of externalities.

Individual recycling schemes, as with other supply options, will present unique opportunities and risks that need to be systematically identified and managed. In ATSE’s view, the Australian Guidelines for Water Recycling provide an appropriate framework for managing community safety and guiding responsible decision-making.

Ultimately, water supply decision-making should be based on an objective assessment of available water supply options to identify the most economically, environmentally and socially sustainable solution. While optimum solutions will continue to be case-specific, ATSE is convinced of the technical feasibility and safety of drinking water supply through DPR when properly managed. ATSE considers there may be considerable environmental, economic, and community benefits of supplying highly treated recycled water direct to drinking water distribution systems in appropriate circumstances.

ATSE therefore concludes that DPR should be considered on its merits – taking all factors into account – among the range of available water supply options for Australian towns and cities. Furthermore, ATSE is concerned that DPR has been pre-emptively excluded from consideration in some jurisdictions in the past, and these decisions should be reviewed.

Governments, community leaders, water utilities, scientists, engineers and other experts will need to take leadership roles to foster the implementation and acceptance of any DPR proposal in Australia.

It is proposed that these findings are highly relevant to the consideration and implementation of the alternative operational strategy for the WCRWS proposed in this submission.

13 Concluding comments

I consider this inquiry to be of great significance to the city of Brisbane and to the State of Queensland in general. As such, I wish the State Development, Infrastructure and Industry Committee well in their important task of identifying opportunities to improve the cost/benefit relationship of water infrastructure assets in South East Queensland. I trust that long-term visionary planning will be a key characteristic of this process.

I hope that you will find the information and proposal that I have provided to be constructive, insightful and thought-provoking. Nonetheless, I anticipate that it may raise a number of additional questions for consideration.

I would be most happy to provide any clarification or additional information that may be requested. Furthermore, copies of all cited documents can be provided upon request.

Sincerely,

Stuart Khan.

14 References

Arnold, R. G., Sáez, A. E., Snyder, S., Maeng, S. K., Lee, C., Woods, G. J., Li, X. and Choi, H. (2012) Direct potable reuse of reclaimed wastewater: it is time for a rational discussion. Reviews on Environmental Health, 27(4), 197-206. Gardner, T. and Dennien, B. (2007) Why has SEQ decided to drink purified recycled water? In: Water Reuse and Recycling (Eds, Khan, S. J., Stuetz, R. M. and Anderson, J. M.) UNSW Publishing, Sydney. Khan, S. J. (2011) The case for direct potable water reuse in Australia. Water: Journal of the Australian Water Association, 38(4), 92-96. Khan, S. J. (2013) Drinking Water Through Recycling: The benefits and costs of supplying direct to the distribution system. A report of a study by the Australian Academy of Technological Sciences and Engineering (ATSE). ISBN 978 1 921388 25 5. Leverenz, H. L., Tchobanoglous, G. and Asano, T. (2011) Direct potable reuse: a future imperative. Journal of Water Reuse and Desalination, 1(1), 2-10. SeqWater (2013a) Annual Report 2012-13. Delivering Value. SEQWater (2013b) www.seqwater.com.au Website: Accessed: 18 October, 2013. Tchobanoglous, G., Leverenz, H. L., Nellor, M. H. and Crook, J. (2011) Direct Potable Reuse: The Path Forward, WateReuse Research Foundation and Water Reuse California, Washington, DC. Thompson, T. (2013) Brisbane suburbs nearly ran out of water as flood torrent shut down Mt Crosby treatment plant In: The Courier Mail Brisbane, QLD. US Environmental Protection Agency (2012) Guidelines for Water Reuse, Washington, D.C.

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